Autonomous boat design for tandem towing

ABSTRACT

A boat that operate autonomously or by remote control, and may be operated without on-board personnel (unmanned) or may be operated in conjunction with onboard personnel, and to methods of using such boats at sea.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related to co-pending U.S. patent application Ser.No. 15/094,948, with a filing date of Apr. 8, 2016, entitled “AUTONOMOUSWORKBOATS AND METHODS OF USING SAME”, the content of which is herebyincorporated by reference in its entirety herein.

FIELD OF THE INVENTION

The present invention generally relates to boats that operateautonomously or by remote control, and may be operated without on-boardpersonnel (unmanned) or may be operated in conjunction with onboardpersonnel, and to methods of using such boats at sea.

BACKGROUND

Autonomous vehicles have entered the world in several embodiments, fromself-driving automobiles to self-piloted drones for package delivery andreconnaissance. Various autonomous sea-going vehicles have beendescribed as well, for use in automated data collection activities. Thefirst sea-going autonomous vehicles were probably torpedoes, executingpreprogrammed travel paths.

“Autonomous” means “no direct human intervention in the controlfunctions.” Self-contained, environmentally aware in a way that enablesdecent control, and sufficient processing figure out what to do next.“Partially autonomous” may also mean that the autonomous boat follows apre-determined path supplied by a user, as best it can. Herein isdescribed an “autonomous control boat” for use in a variety ofsituations where manned operation is either expensive or dangerous, orextremely difficult to manage.

In an embodiment, the autonomous or unmanned boat described hereincomprises an unmanned powered marine platform that may be used to towanother in-water object or objects independently. Autonomous towingfurther comprises a mechanical connection between the autonomous vehicleand the towed object, which may further comprise a metal cable, wire, ortow rope or a tow line or a chain, or any other suitable linkageincluding rigid or semi-rigid elements. A tow cable may be part of awinch system for controlling the separation between boat and in-waterobject. Monitoring and controlling the tow cable is essential for propercontrol and towing operation, and is described further in a subsequentsection.

In an embodiment, the autonomous boat may work with at least one otherconventionally-piloted or autonomous boat to accomplish a tandem towingmovement of one or more other in-water objects. Thus there are twodifferent modes of operation: independent, single boat operation, andinterdependent, collaborative operation with two or more boats operatingin conjunction one or more in-water object.

In an embodiment, the autonomous or unmanned boat described hereincomprises an autonomous powered marine platform that may be used tocollaborate with another master vessel to increase the capability andproductivity of an in-water operation. The autonomous vessel can beprogrammed to operate in a position and heading that is relative themaster vessel. The autonomous vessel can collect in water, above water,or sub-bottom sea-floor data or information.

SUMMARY OF THE EMBODIMENTS OF THE INVENTION

The functionality needed for many of the operations of an autonomousboat may be summarized as “core” functions. They are:

Specialized Processors for Automated Autonomous Operation

Environmental Awareness System

Determining the Location and Orientation of the Boat

Environmental Sea-State System

Maintaining a Stationary Position

Obstacle Avoidance

Transiting to a New Location

These activities are further described in subsequent text and shown inthe accompanying FIGS. 1-7.

In addition, there are several specialized activities that theautonomous boat can perform. These include:

Serving as an automated tugboat:

-   -   Managing the Towing Operation    -   Performing Boat Guidance and Control Functions for Towing        Performing pollution control activities, including oil spill        containment and abatement

Performing Collaborative Activities

Collaborative activities include working with additional conventional orautonomous boats to emulate tugboat functionality, controlling tetheredand un-tethered undersea vehicles, or providing force multiplication ofa mothership by expanding a survey swath. Examples are also shown inFIGS. 8-15.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part ofthe specification, illustrate various embodiments and, together theDescription of Embodiments, serve to explain principles discussed below.The drawings referred to in this brief description of the drawingsshould not be understood as being drawn to scale unless specificallynoted.

FIG. 1 shows a System Block Diagram for the integrated control systemthat controls the boat actions and activities.

FIGS. 2A and 2B show Block Diagrams for an Environmental AwarenessSystem that takes multiple data sources into account to create anEnvironmental Status Report.

FIG. 3 is a flow chart (1) that describes the steps performed by theintegrated control system when determining where the boat is located.

FIG. 4 is a flow chart (2) that describes the operation of theEnvironmental Sea-State System previously described in FIG. 2.

FIG. 5 is a flow chart (3) that describes the operation of the controlsystem when keeping the boat in a stationary position.

FIG. 6 is a flow chart (4) that describes the operation of the controlsystem where the operation is to avoid a possible collision with anotherobject.

FIG. 7 is a flow chart (5) that describes the operation of the controlsystem where the operation is to move to a new location.

FIG. 8 is a flow chart (6) that describes the operation of the controlsystem where the operation involves the management of collaborativeactivities.

FIG. 9 depicts a typical collaborative activity involving an oil spillcontainment process.

FIG. 10 is a flow chart (7) that describes the operation of the controlsystem where the operation is performing pollution control activities,such as shown in FIG. 9.

FIG. 11 is a flow chart (8) that describes the operation of the controlsystem when it is performing management of an undersea vehicle.

FIG. 12 is a block diagram depicting a system for measuring andcontrolling tow line position and tension and providing managementinformation.

FIG. 13 is a flow chart (9) that describes the operation of the tensionmonitor system.

FIGS. 14A and 14B are diagrams depicting the guidance calculations fordetermining a propulsion vector direction for towing a vessel to adesignated waypoint.

FIG. 15 is a flow chart (10) that describes the operation of a pair ofautonomous boats operating in a master-slave relationship for towing avessel.

FIGS. 16A and 16B are block diagrams depicting an autonomous underseavehicle being controlled by an autonomous boat via a wireless and wiredlink.

The figures are provided in order to present a thorough understanding ofthe present invention. The figures should not be construed as limitingthe breadth of the invention in any manner.

SUMMARY OF EMBODIMENTS OF THE INVENTION: CORE FUNCTIONS

The essential difference between the prior art and currently describedautonomous boat functions lies in the way an overall model is createdfor vehicle behavior of the autonomous control boat. In an embodiment ofthe invention, this model takes into account the behavior of the targetdevices that need herding and control. In an embodiment of theinvention, aspects of the model are integrated with knowledge of the seastate. In an embodiment of the invention, the autopilot system is fullyintegrated with the sea-state data and the two devices, the boat and thetarget device. The big difference between what a human does by remotecontrol and remote observation lies in the experienced processing in ahuman brain of the data about the 3 states: boat, target, and sea. In anembodiment of the invention, herein is created a sufficiently completemodel that lets a computer do a credible job of standing in for a human.Human override in the event of some unexpected change in the threestates, for example, may necessitate some kind of intervention.

In an embodiment of the invention, the heart of the autonomous controlsystem is a vehicle controller computer (low level), guidance and taskmanagement computer (high level), data input from a combination of a setof sensors, data output to vehicle control machinery, andcommunication/data link to a remote user station. The overall productconsists of a series of programs for each of the cited elements, and amain control program.

The location/orientation “state” of an object referred to is defined byat least 6 parameters: roll, pitch, and yaw, and x, y, and z. Roll,pitch, and yaw may be determined by a combination of a 3-axisaccelerometer and a compass or magnetometer or a gyroscope. In anembodiment of the invention, well-known methods for determiningorientation from at least 2 sensors are incorporated.

Position in terms of x, y, and z coordinates may be found from GPS/GNSSreceivers. Determining location with GNSS/GPS anywhere on earth withaccuracy better than 1 meter is commonplace today, via error correctionsystems. For high performance operations, various alternate positioningmethods using GPS such as DGPS, RTK or RTX can provide sub-meteraccuracy.

In an embodiment of the invention orientation of the autonomous boat maybe determined from a variety of sensors associated with theEnvironmental Awareness System, including an inertial navigation system(INS), a compass (gyro or magnetic), Differential GPS (DGPS), or may bederived from a series of GPS/GNSS position measurements made over ashort period of time, from which heading may be extrapolated.

In an embodiment of the invention, image sensors can be employed toindicate proximity to nearby objects including reference points on thetarget, other neighboring objects, buoys, potential hazards, and thelike. In an embodiment of the invention, stereo pairs of imagers canprovide photogrammetric-derived distances to precise locations on thetarget vehicle. In an embodiment of the invention, bulls-eye targets canbe affixed to points of interest on the target vehicle with real-timemeasurements of pre-arranged distances, again, for use by the statemachine and autopilot. In an embodiment of the invention, electronicdistance measurements [EDMs] via laser may be used in lieu ofphotogrammetric methods. Such EDMs may be implemented with radar, sonar,or lidar systems.

Defining the “sea state” is a well-known requirement but is stillevolving process. In an embodiment of the invention, data may beobtained from sensors external to the boat and the target object, aswell as on the boat itself. Sea state can be measured when the boat isunder way by motive power or not under way and is just ‘floating.’Temperature, air pressure, wind speed, water depth, and wave state allenter into the instant condition estimate of the sea-state.

In an embodiment of the invention, once the various states are known andupdated in real time, and a selected work flow guidance/control plan isentered into the guidance and task management computer, this computercan deliver commands to the propulsion and steering system to performthe desired movement of boat and target, while taking account of boatstate, target state, and sea state.

In an embodiment of the invention, there are multiple types ofnavigation/control objectives, some of which are described in thefigures demonstrating flow chart operations. In an embodiment of theinvention, a remote setup function is invoked by a master controller[machine or person] to set the desired functions in motion according toa pre-planned sequence. Herein is described the variety of controlfunctions needed to implement most of the tasks put forth in theprovisional patent.

In an embodiment of the invention, data acquisition of a target state oflocation and orientation may be obtained by use of small integratedwireless position/orientation sensor(s) affixed to target, such as theTrimble® Leap product.

In an embodiment of the invention, multiple methods may be used toautomatically affix a remote sensor to a target, or to affix a referencebullseye target. For example, in an embodiment of the invention, a crossbow with an arrow carrying a sensor is launched toward the target, andaffixes itself to the target with a glue material on back side of thesensor. Any other suitable launch system may be used as well.

In an embodiment of the invention, photogrammetric or electronicdistance measurement may be made via LIDAR or SONAR or RADAR toreference points on the target vehicle, and to nearby objects in thevicinity of the autonomous boat. For example, in an embodiment of theinvention, a pair of cell phones may be used to obtain images that canbe processed to determine distance and orientation of a remote target onan object.

In an embodiment of the invention, automatic maneuvering with precisealignment with a target object like another boat may be done via apre-programmed operation. This capability is essential for fullyautomatic unmanned operation in order to bring the autonomous boat to adock, or to work with another autonomous boat where both boats areoperating as tugboats.

In an embodiment of the invention, a high performance propulsion systemis incorporated. Additional control mechanisms for added maneuveringflexibility via 360 degree azimuth propulsion systems or more than onesource of propulsion wherein one or more jets are provided. Suchpropulsion systems may comprise water jets with nozzles that can rotate360 degrees about a vertical axis. The autonomous tugboat may alsoutilize additional auxiliary thrusters for heading or station keepingcontrol.

Other embodiments for improved propulsion control may comprise use of apropeller system with similar rotational range of operation about avertical axis. Such a propeller system may comprise reversible directionpropellers.

In an embodiment of the invention, automatic safety overrides based onpreset conditions that are compared to Environmental Awareness Systemdata inputted to a suitable state machine [program] may determine whento activate corrective measures by the autopilot.

Embodiments of the Invention: Tugboat Operation

In an embodiment of the invention, the autonomous boat is programmed tofunction as a tugboat. Synchronized guidance/control of multipleautonomous tugboats can perform synchronized movement of target objects,as tugboats do. The autonomous tugboat may work collaboratively with atleast one other conventionally operated boat or autonomous boat toaccomplish a multi-platform task whereby each singular tugboat is towinga separate in-water object or tandem-towing one object or linked stringof objects. Coordination with the towed or guided vessel and a possiblesecond autonomous boat may be done via a pre-programmed operationinvolving several of the functional control elements described hereinand shown in the figures. Such pre-programmed operation may requirecontrol functions that meet the needs of the overall operational goal,but are not the same as if the towed/guided vessel were operating underits own power.

Tow lines are often used to connect the autonomous tugboat to a vesselto be towed. Maintaining a controlled level of tension in the tow lineis essential to completing the mission without breaking the tow line. Inan embodiment of the invention, tension measurements in the tow line maybe made via strain gauge sensors embedded in the tow line, and saidmeasurements are coupled to a wireless communication system, such asthat widely implemented by Bluetooth hardware and systems, form anadditional input of an important condition into the autonomy computer.The data feed from a strain gauge may be used to adjust and control thepropulsion and steering of the autonomous tugboat to maintain desiredtension and desired direction of travel. Tension and shock data may becollected and maintained for continued evaluation of tow line stress. Inthe event the accumulated stress exceeds a specified threshold, an alertmay be activated indicating there is a risk of failure, even at reducedtension levels.

In an embodiment of the invention, two boats may serve as a pair ofoperating tugboats, with one or both being autonomous. In an embodimentof the invention, a first boat is designated as the “Master” or“Mothership” and the second boat is designated as the “Slave” or“Daughter Vessel”. In this configuration, the Master tugboat determinesor receives a course and heading, or a series of waypoints created by aperson in command of the operation, as shown in FIG. 1 whereinstructions from a Remote Home Base are radioed to the control systemon the autonomous boat. The course and heading or waypoints define thepath that the towed vessel should follow. In a second program operativeat the Master, a second set of waypoints is determined for theautonomous boat to follow so that the towed vessel follows the first setof waypoints. The second set of waypoints is determined dynamically bythe autonomy computer and takes account of the Environmental AwarenessSystem inputs regarding wind, wave action, sea-state, and current flow.This towing guidance course is dynamically adjusted over short timeperiods, on the order of seconds to minutes, depending on theenvironmental conditions.

In a first aspect, the present invention relates to a method forpropelling a target boat via an unmanned boat having autonomousnavigation/guidance. control, and propulsion systems for moving targetboat along a pre-determined guidance path for said target boat. In someembodiments, the method includes: providing a linking system for joiningthe target boat to the unmanned boat to enable propulsion of target boatby unmanned boat; providing a sea-state sensor system for accounting forcurrent sea state of the environment of the target boat and the unmannedboat; providing a position/orientation sensor system for said targetboat; providing a position/orientation system for said unmanned boat;providing an Autonomous Control System for accounting for sea state.orientation/position of target boat and unmanned boat, andpre-determined path, wherein Autonomous Control System determinescommand/control instructions for the propulsion system; and wherein saidpropulsion system receives commands for directing unmanned boat fromautopilot system to propel target boat along the pre-determined path.

In some applications, the method may include one or more of thefollowing: the current sea state may be determined in real time; theboat position/orientation/heading may be determined in real time; acomputer-based Graphical User Interface may be used by a Remote Operatorto provide high-level commands wirelessly to the Autonomous ControlSystem on the autonomous vessel, such as waypoints, or pre-determinedpath. In some variations, the Autonomous Control System is furtherconfigured to receive override commands from a mother ship wirelessly.

In a second aspect, the present invention relates to a method fordetermining a control command/function for a propulsion system on anunmanned autonomous boat. In some embodiments, the method includes:providing an autonomous control system configured to receive positionand orientation information for said unmanned autonomous boat; providingsea-state data, vessel motions and acceleration values, and wind datafor the environment of the unmanned autonomous boat for input to theguidance and navigation system; providing a navigation route and speeddata for guiding the autonomous boat to a selected designation to theguidance and navigation system at a pre-determined velocity: providingan override control input to the autonomous control system for alteringthe navigation route/speed via a remote input; providing an algorithm[in a real time filtering system] in the autopilot system to integratethe sea-state data, the position/orientation data, the navigation routeand speed data, and the override control data to determine a propulsioncontrol signal for the propulsion system and steering control signal forthe steering control system.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 depicts the fully integrated control system and environmentalawareness system in a block diagram. A computing processor systemcontains the essential elements: Hardware memory, Random Access Memory[RAM], Read Only Memory [ROM], the processor/CPU, an Input/Output port,and software modules that provide an operating system, with a variety ofapplications.

Attached to the Processing System are a number of devices. A PeripheralReadable Storage Medium is typically located external to the ProcessorSystem, and may be implemented via a rotating medium hard drive oranother RAM such as may be found implemented in memory sticks as anEPROM.

A Remote Home Base block represents the remotely located control centerwhich contains a variety of data management systems, processors, and aradio link for communicating with the autonomous boat's control system.The Remote Home Base is equipped to formulate and send commands, and toreceive status reports from the Processing System. It may be manned orunmanned.

Programs and commands may be sent directly to the Processing System viathe radio relay link, from the Remote Home Base to the correspondingradio receiver/transmitter system on the autonomous boat, as shown inthe box labeled “Radio Link On Board.” The Operating System of theProcessor System is configured to receive pre-programmed instructiondata packages, store them, and access them according a set ofinstructions associated with the Operating System. Alternatively, thepre-programmed instructions may also include start-up instructions forexecuting the remainder of the instruction set in the pre-programmeddata package.

The autonomous boat control system is configured to operate in any ofthree modes: Remote Control, Manual Local Control, or Automatic Control.

If the boat is unmanned, then the Remote Home Base has priority forcontrolling the processor operation, under Remote Control. The RemoteHome Base an initiate a series of pre-programmed operations. Typicallysuch operations involve feedback from the Processing System regardingthe status of any such operation, enabling the Remote Home Base to abortany operation according to pre-arranged rules, and begin a new operationas may be selected by Management at the Remote Home Base.

Alternatively, in an embodiment, a person may take control of theautonomous boat via a command to the Mode Select function. Such localcontrol may enable continued autonomous operation, or manually inputtedcommand operation.

To that end, there is a display connected to the Processing System busto enable local observability of all control functions, including statusof the sea state as determined by the Environmental Awareness System,shown as an attached functional block to the Processing System.

In an embodiment, the Processing System is integrated with an ExternalTool Control module, for use in activating and operating external toolssuch as oil collection booms. Other such automated tool managementsystems may be similarly implemented. Elements of this module mayrequire individual customization to suit the needs of the specific tool.

In an embodiment, the Processing System is connected to the PropulsionSystem for activation and control of the Propulsion System.

The following descriptions of embodiments of the invention address thesubsequent figures after FIG. 1.

2. FIGS. 2A and 2B Environmental Awareness System

FIG. 2A depicts a block diagram of an Environmental Awareness System[EWA]. The components of the Sea-State System comprise a computerprocessing system for executing a series of algorithms and commands anda Sensor Communications System for obtaining environmental sensing datafrom a variety of sensors subsystems. The sensor subsystems furthercomprise a Weather system, a Water System, and Location System, and anOptical Sensor system. An integral part of the Environmental AwarenessSystem [EWA] is a group of sensors for estimating the sea-state.

In an embodiment, the Weather subsystem measures air temperature, windspeed, and wind direction, and provides this data to the SensorCommunication System. The Weather system measures precipitation andprovides it to the Sensor Communications system.

In an embodiment, the Water system measures water temperature,turbidity, wave action from a local inertial navigation system data,water current speed and direction of current flow, and provides thisinformation to the Sensor Communications system. Wave action may bedetermined from INS data by reading the vertical excursion delta Y ofthe INS system from the x, y, and z coordinate displacements over agiven time period.

In an embodiment, additional information may be provided by an optionalinertial navigation system. Both the GNSS/GPS and the INS system canprovide data covering the direction of travel path followed by theautonomous boat from the time it leaves a mooring until its return.

The omnidirectional camera and the directed camera were describedpreviously. The cameras are monitored, controlled and their data isprocessed by the computer processing system.

The data generated by the computer processing system are contained inthe Environmental Report. In an embodiment, the data comprises WeatherData, Location information, Direction of Travel, Drift and Currentspeed, water temperature, turbidity [water clarity], an estimate of theSea State, the presence of any nearby objects, and any potentialcollision status.

In an embodiment, the Sea State information comprises wave height[distance from wave trough to crest], wave period, wave-length, wavesteepness [the ratio of wave height to the wave-length], wave speed,time between crests passing a point, and overall power spectrum. Thisdata may be derived from the INS system. Sea State is also defined bythe Beaufort number, which takes wind speed, waveform and height intoaccount.

In FIG. 2B, a flow chart for determining the Sea State is depicted. Thesteps comprise collecting data from the sensors, evaluating the dataaccording the predetermined metrics, processing the data to obtainappropriate metrics, and comparing the data to standard Sea Statereference data to determine a Sea State metric.

3. FIG. 3 Flow Chart 1 Where Am I?

Flow Chart 1 depicts the steps for determining and updating a positionfix for the autonomous boat.

The autonomous boat has at least one of a GNSS/GPS or DGPS receiver,radio beacon system, fan-beam laser target system, and optionally mayhave an omni-directional camera for assessing the sea-state and physicalenvironment.

The operating system used to implement the “Where am I?” functionalitystarts at step one where is it determines whether GPS GNSS is available.If GPS/G NSS is available, it obtains a position fix and it delivers itto the Sea-state system. This operation is repeated on a continuoussub-second basis until the system is turned off.

In the event that the DGPS or GPS/GNSS positioning systems are notavailable, the Autonomy Computer sends an alarm to the Remote OperatorStation and reverts to an automated Dead Reckoning System that reviewsthe speed and drift data from before the real time positioning systembecame unavailable and uses the information to calculate and estimatethe continuing course of the vessel. The Autonomy Computer willimmediately revert back to DGPS or GPS/GNSS when available and make anynecessary vehicle corrections.

In an embodiment, a camera can be used for vehicle positioning which maybe conventional cameras or an omni-directional unit configured to have a360 degree horizontal and vertical field of view Images captured aresent to a processing system for comparison with stored images of thecoastline in the region of interest. If a match is found with a storedimage, the location may be determined by taking additional images atdifferent locations, wherein photogrammetric mage processing methods candetermine a location of the autonomous boat.

In an embodiment, images taken by the omni-directional camera may beused to determine horizontal orientation of the autonomous boat bypattern matching of coastline images. This could be important if theautonomous boat is not able to move. If the boat can move, thenorientation may also be found from sequential GPS/GNSS position fixestaken at different locations.

In an embodiment, an alternate camera may be employed in which thecamera has non-omni-directional field of view with a variable focallength lens. In an embodiment, this camera may be remotely controlled toaim in a desired direction. In an embodiment, this camera may beremotely controlled to adjust the focal length to obtain a zoomed-inimage.

In an embodiment, any of these two types of cameras may obtain imagesthat can be analyzed by the image processing system resident as a set ofalgorithms available to the computer processing system, to determine fogconditions and infer visibility.

In an embodiment, camera or video data and even 360-degree images orvideo is passed or streamed from the vessel in real time to a RemoteOperator Station so that a person can pilot the boat remotely. The360-degree video or images can be displayed on desk top, wall mounted,or tablet screens or be viewed on virtual reality (VR) goggles orglasses that are worn by an operator and use local referencing to seeany part of the 360-degree video or image by movement of the goggles orglasses.

4. FIG. 4 Environmental Sea-State System

In FIG. 4, The Sea State system operation starts and activates thesensors. The next step is to collect data from the activated sensors,including weather data, water data, location data and optical imagedata.

The next step describes processing the water data to determineswell/wave amplitude and water turbidity. The next step describesprocessing the location data, water data, INS data, and weather data todetermine position, wave direction, current direction, boat traveldirection, and amplitude of boat motion in terms of roll, pitch and yaw.

The next step describes processing the optical image data from thecamera[s] to determine a visual estimate of the surface of the sea, anynearby neighbors, any fog condition, and coastline location relative toboat location and orientation or heading. The next step shows that thecomputer processing system updates the Environment and Sea-State report.

5. FIG. 5 Flow Chart for Maintaining a Stationary Position

FIG. 5 depicts a Flow Chart for a standard operation called MaintainStationary Position. The goal of this operation is keep the autonomousboat in a stationary position and a constant heading direction.“Stationary” is relative to a reference position determined by theLocation system, and chosen by a pre-programmed operation implemented inthe Computer Processing system. Upon receipt of a command to initiateMaintain Stationary Position, the first step in the operation commandsthe control element of the computer processing system to access theEnvironmental Sea-State system to obtain data on the location, heading,wind speed and direction, current speed and direction. In the next step,the computer processing system determines a net vector direction thatwould be moving the boat if it were not operating any propulsion system.The control system determines the opposite direction and magnitude ofthrust for the propulsion system to exactly counteract the net externaldirection of the various external forces acting on the autonomous boat.The control system has a set of data that relates likely boat motion tothe magnitude and direction of forces from wind and current and waveaction. In the next step, the control system activates the propulsionsystem to apply a thrust vector to maintain a constant position. In anembodiment, this thrust vector is updated second by second. In anembodiment, the update rate may be altered to suit the application, andmay be faster or slower than once per second. In an embodiment, thethrust vector may be operated in a pulsed mode or a continuous mode.

6. FIG. 6 Obstacle Avoidance Maneuver

FIG. 6 depicts a flow chart for implementing a collision avoidancemaneuver. The control algorithms for collision avoidance start byaccessing the Environmental-Sea-State System to obtain optical systemdata and optionally RADAR data, or optionally an LIDAR data. LIDARrefers to optical signal measurements of distance and bearing, likeRADAR, but at light frequencies, or wavelengths. The first operationcompares instant optical imagery to previous optical images to check tosee if there are any nearby neighboring craft. This test is donecontinuously on new imagery captured on a periodic basis. The time framemay be as often as once a second, or faster, but may also be slower,such as once every 10-30 seconds. If a change in the imagery occurs, thenext step in the operation is to increase the rate of image capture. Thecollision avoidance system next determines the direction of travel ofthe oncoming object, and then determines a rate of closure. If thedirection of travel appears to be toward the boat, within a specifiedrange of vector direction of approach, the next algorithm operates todetermine an evasive maneuver direction and speed. The next algorithmestimates the time to collision based on estimating the speed of closurefrom a series of images, or based on radar data, and calculates the bestevasive maneuver. When the rate of closure exceeds a specified speedlimit, the collision avoidance system activates the evasive maneuverimmediately.

7. FIG. 7 Flow Chart for Moving to a New Location

FIG. 7 depicts the steps for moving the autonomous boat to a newlocation.

The first step for the control algorithms in this operation is obtainand receive a list of sources which are authorized to command the boatto move to a new location. This step may include encryption anddecryption of authorized source identification to prevent unauthorizedagents from highjacking the boat. Additionally there may be moreauthentication activities. This list of authorized sources may beupdated according to a prescribed rule, such as once an hour, or once aday, or any other rate, as may be preferred by the remote operator.

The next step is to receive and accept a command from an authorizedsource to move to a new location, specified by position coordinates suchas latitude and longitude, or any other desired coordinate system.

In the next step, the control system determines the vector directionfrom the boat's current location to the specified destination. In thenext step, the control system obtains data from the EnvironmentalSea-State system to account for wind and current direction and strength.The control system calculates a thrust vector for the propulsion system,taking the environmental conditions into account, and the desiredarrival time, if specified in the authorized “Move to” instructions. Thecontrol system specifies a command for the propulsion system. In thenext step, the control system confirms to the remote authorizationsource that it will execute the propulsion system command. Depending onthe original message setup from the authorized source, the command maybe executed directly by the control system without needing aconfirmation from the remote source. Upon arrival at the specifieddestination, the control system may inform the remote authorizing sourcethat the boat has arrived and is on station.

8. FIG. 8 Flow Chart Collaboration Management

FIG. 8 depicts a flow chart describing the steps to be taken whenentering into an operation in conjunction with at least one otherautonomous boat.

The first step as shown in FIG. 8 defines the creation of a location mapfor the array of boats that will participate in the joint operation. Atypical kind of operation is the deployment of booms with netting tointerdict an oil spill by surrounding the oil spill with boats and theirnetting. An Operational Management activity, optionally located remotefrom the complement of autonomous boats participating in thecollaboration activity, defines the location for each boat, and createsa Move-To command for each boat, so that each boat takes a position atthe designated location. In the next step, the Operational Managementactivity delivers the map of all locations and a specific command toMove-To a specified location for each boat participating. Optionally,the Operational Management activity may request confirmation from eachboat regarding how each boat knows the desired location and has aMove-To command to implement the propulsion command to go to the newlocation in the collaboration activity. In the next step, theOperational Management activity issues a command to deploy thecomplement of boats, which then commence moving to the desiredlocations. When each boat arrives at its specified location, it sends amessage to the Operational Management activity indicating it is “onstation.” Once all the boats are on station at the specified locationsand in the proper orientation as specified by the Move-To command toeach boat, the complement of boats is ready to commence a specifiedmaneuver. For the case where the specified maneuver is to contain an oilspill, an example of an operation activates the deployment of an oilspill boom system, which results in a boom being extended from theautonomous boat, releasing a confinement netting, spreading it out sothat the netting systems from each boat extend from each boom on eachboat and form a closed circular oil spill fence. An oil collection boatmay be stationed nearby to aid in the collection of oil from the spill.

9. FIG. 9 Collaborative Activity

FIG. 9 depicts an example of collaborative activity involving an oilspill containment activity. Seven autonomous boats are positioned sothey surround a portion of an oil spill. A spill collection boat framesthe remainder of the oil spill.

10. FIG. 10 Flow Chart for Pollution Management

FIG. 10 is a flow chart for a typical pollution control operation atsea. The autonomous boat fleet receives a series of data and commandswherein a list of estimated locations is provided as to where each boatin the fleet is to navigate, take up a position and maintain it, and toorient itself in a specified direction. In this type of operation, thereare commands for reporting current location, orientation, and status.Camera imagery from the Environmental Awareness System is essential toproving that the fleet of autonomous boats are in the right location andthe in the right orientation. Once the proper location and orientationfor each boat is proven, the deployment of the collection system boomscommences. Again, camera imagery may provide both confirmations ofproper operation as well as mid-course guidance updates regarding boomand containment operation.

11. FIG. 11 is a flow chart describing the steps taken to operate anundersea vehicle. Typically this operation is designed to obtainmeasurement data from the sea floor, or for other types of informationgathering. In an embodiment, a first mode of operation for the underseavehicle is fully autonomous. In an embodiment, the autonomous boat has awireless communications link to the undersea vehicle. In an embodiment,a second mode of operation comprises a cable connection between theautonomous boat and the undersea vehicle, whereby the autonomous boatmay tow the undersea vehicle according to a preplanned path. In anembodiment, the towing cable may also comprise a direct, wiredcommunications link to the undersea vehicle.

In either of the two modes of operation, a first step is to test andprove that a communications link is operative between the autonomousboat and the undersea vehicle. The next step is to obtain a set ofinstructions for the undersea vehicle. These instructions may be radioedfrom the Home Base or obtained from a non-volatile memory device like amemory stick provided to the autonomous boat before it leaves port. Oncethe set of instructions is downloaded to the undersea vehicle,additional operational checks are performed to assure proper operationof the undersea vehicle. The set of commands may include instructionsfor diving to specified depth levels, or to the sea floor, and collectdata at various stages of the undersea operation. Depending on theconnection between the undersea vehicle and the autonomous boat, thedata may be relayed back in real time, or uploaded to the autonomousboat control system upon returning to the autonomous boat.

In an embodiment, the undersea vehicle may comprise a survey tow fish ora camera sled for capturing images of points of interest. In anembodiment, other sensors may be employed to collect data of a specificnature, such oil content or other minerals. In an embodiment, the toweddevice may need to maintain a specific distance from the sea floor. Thisdepth control function may be implemented by monitoring the sea-floordepth and the in-water speed. In an embodiment, when the underseavehicle is being towed, the tow cable payout length may be controlled bya suitable control system as an aid to manage the depth controloperation. In an embodiment, the towed undersea vehicle may comprise atleast one depth measurement device to determine the towed underseavehicle height above the sea floor. In an embodiment, this depthmeasurement may be used by a depth control system in the underseavehicle to directly control height above the sea floor, via the underseavehicle propulsion control system.

In an embodiment, the location of a towed object relative to theautonomous boat may be determined by elements of the EnvironmentalSea-State System, including the image capture system. In an embodiment,a GPS/GNSS receiver system may be located on the towed object, and theGPS/GNSS location data may be radioed to the autonomous boat controlsystem via a suitable radio link, such as a Bluetooth short-rangesystem.

In an embodiment, location information and operational statusinformation may be collected by the Processor System, formatted andpackaged for data transmission to a Remote Home Base, as shown in FIG.16A, 16B and in FIG. 1.

12. FIG. 12 Tow Cable Tension Monitoring System

FIG. 12 depicts a block diagram for a tow cable tension monitoringsystem. The cable tension is measured by a strain gauge that is embeddedor otherwise attached to the tow cable in a manner that determines thetension level of the tow rope. The strain gauge is connected to aBluetooth short-distance radio relay system that transmits strain datato a monitoring system which is connected to the autonomous boat'scontrol system, as shown in FIG. 1. In an embodiment, the monitoringsystem may have stored reference data for acceptable tension limits fora variety of tow cables. In an embodiment, a manager of the autonomousboat may input a limit for a given application and a particular towcable being used.

13. FIG. 13 Flow Chart for Tow Cable Management System

Once a tension limit is set in the tension measurement system as shownin FIG. 12, the tension system is ready to operate. FIG. 13 depicts thesteps in performing a real-time monitoring function of tow cabletension. The strain gauge local tension measurement system is poweredon. In an embodiment, the local measurement system may bebattery-operated, or powered by boat power via a power cable. In anembodiment, the strain gauge measurement sensor may monitor the tensioncontinuously, or it may do the measurement periodically, on a sampledtime basis. The instant measurement of tension is compared to a storedreference tension. If the tension in the tow cable exceeds the specifiedtension limit, a signal indicative of the tension value is created andsent to the control system of FIG. 1. The control system may make anadjustment to the propulsion system to reduce the speed of the boat, orit may reduce the tension by adjusting a winch to lengthen the tow cable[“pay out the cable”.] Real time feedback regarding the amount oftension in the tow cable may be used to adjust the autonomous boatpropulsion thrust level to reduce speed and therefore reduce tension,and minimize the effects of sudden shocks. The real time feedback may berelayed to Home Base for monitoring or for remote control adjustment ofthrust and therefore speed.

14. FIGS. 14A and 14B Guidance Calculations

FIG. 14A displays a representation of an autonomous towing operationwherein two autonomous boats Aboat1 and Aboat2, are towing a largervessel. The tow cables are not shown in this figure but are attached tothe front end of the towed vessel at typical connection points, and atthe rear end of the autonomous boats. A calculation must be made todetermine the direction of propulsion for the Master Aboat1 and theSlave Aboat2. The desired direction is shown at the circle-X at Waypoint1, at some distance in front of the towed vessel. This Waypoint is alocation in a suitable coordinate system such as Northing and Easting,or X and Y on map grid, or in latitude and longitude coordinates. Thuseach vector has two components, Vx and Vy.

With a known location of the towed vessel, as determined by a GNSS/GPSreceiver, or any other location system for the towed vessel, the vectorfrom vessel to Waypoint1 may be determined by geometric calculationswell known in the navigation arts.

There are at least two other forces acting on the towed vessel and thetwo autonomous boats: wind and current. Vector directions representingthese two forces are shown in FIG. 14A as Current V1 and Wind V2. Theeffective current velocity V1 [speed and direction] is difficult todetermine, but can be estimated by a number of measurement devices whichare available to perform the measurement directly while on the boat. Thepygmy meter, the flow probe, and the current meter can be adapted foruse on an autonomous boat [see Wikipedia for information on “how tomeasure stream flow rate” ].

The wind speed may be obtained from the Environmental Awareness System.The effect of the wind speed on the autonomous boats and the towedvessel must be calculated. The calculation requires knowledge of theeffective wind load cross section of the various vessels as a functionof wind direction [angle of arrival]. The effective wind load is aparameter associated with the vessel being towed, and is an input to thesystem calculating effective speed the towed vessel would experiencewhen the wind blows at it from any given direction. That effective speedis what is used in the following calculations.

The combination of wind and current composite vector direction may alsobe determined by examining the direction of the propulsion system andits speed when the control system is operating the propulsion system tomaintain a steady fixed location. The thrust level needed to maintain agiven position corresponds to an open-water boat speed, which can beobtained by calibration of the boat operation in a closed channel wherethere is little wind and no current flow. The direction is the oppositeto the direction of the propulsion system thrust.

The vectors for the desired direction of travel, Vwaypoint, the currentV1, and the wind V2 are shown in FIG. 14B, along with the propulsionvector Vpropulsion. The combination of V1, V2, and Vpropulsion mustcombine to move the towed vessel along the vector direction ofVwaypoint:1. V1+V2+Vpropulsion=Vwaypoint.Rearranging the terms:1. Vpropulsion=Vwaypoint−V1−V2.

For example: let V1=2 mph at 110 deg [from North, or 20 degrees SE1. V2=10 mph at 130 deg [40 degrees SE]

Let Vwaypoint=10 mph at 30 deg.

The speed components are:V1x=2*cos 20=2*0.94=1.88V1y=−2*sin 20=2*0.34=−0.68V2x=10*cos 40=10*0.77=7.7V2y=−10*sin 40=10*0.64=−6.4Vwaypoint-x=10*sin 30=10*0.5=5.0Vwaypoint-y=10*cos 30=10*0.866=8.66

Table of Guidance Parameters Vector X component Y component Vwaypoint+5.00 +8.66 V1 −1.88 +0.68 V2 −7.70 +6.40 Vpropulsion −4.58 +15.74

The vector direction of the propulsion angle needed is given by thearctangent of Vx/Vy, or arctan [4.58/15.74]=16.44 degrees west of north,as shown in FIG. 14B. The propulsion speed to deliver 10 mph toward theWaypoint is the square root of the sum of the squares of the twopropulsion components, or 16.4 mph.

The Slave boat Aboat2 receives instructions for matching propulsionspeed and direction from the Master Aboat1.

15. FIG. 15 Flow Chart Master-Slave Towing Operation

FIG. 15 is a flow chart describing the operation of a Master-Slavetowing operation. The two autonomous boats performing the towing have anactive two-way radio communications system wherein the Master updatesthe operational requirements for the Slave. The multiple towing boatsare referred to as a “tow set.” The steps start with activating a MasterControl program on the first autonomous boat, and then activating asimilar program on the second autonomous boat. The Master autonomousboat receives a first waypoint toward which the towing operation is toproceed.

In an embodiment, the Master Control determines the propulsion vectorneeded to tow the vessel toward the first defined waypoint, as wasexplained in the previous paragraph 14. The Master Control operationtakes account of the effective wind and the current speeds. Thepropulsion speed and direction of travel for each autonomous boat isactivated by the Master and the Slave boats.

A comparison of actual location to desired location along the path tothe first waypoint is made periodically, as shown in the Flow chart.

The propulsion vector is updated periodically to account for any coursedeviations caused by changes in wind and current speeds. The rate ofupdate is variable depending on the weather conditions. Update rates mayvary from once a second to once a minute, or even longer.

As a first waypoint is approached, a second waypoint may be defined andthe propulsion vector may be recalculated, as shown in the Flow Chart inFIG. 15.

In an embodiment, the master boat may be manned instead of beingautonomous, and the second slave boat may be an autonomous unmannedboat.

In an embodiment, the slave boat may operate with different controlalgorithms, which enable a complementary path for the slave boat tofollow, particularly when making path guidance changes involving turns.Both the master and the slave have the capability of adjusting tow cabletension, as described in para. 13 and shown in FIG. 13.

16. FIGS. 16A and 16B Autonomous Boat & Undersea Vehicle Block Diagram

FIG. 16A depicts two versions of the combination of an autonomous boatoperating an undersea vehicle. In an embodiment, the first version inFIG. 16A depicts an autonomous undersea vehicle being controlled by anautonomous boat. In an embodiment, there is a communications linkbetween the surface vessel and the subsea vessel. In an embodiment, thiscommunications link may comprise a sonic communications system. In anembodiment, the communications link may comprise an opticalcommunications system. In an embodiment, the communications link maycomprise short-range radio communications system.

In an embodiment, the second version in FIG. 16B depicts an autonomousvehicle being controlled by an autonomous boat via a direct cablecommunications system, further comprising a wired system. In anembodiment, the communications system may comprise an optical systemusing fiber optics for the connection between the autonomous boat andthe undersea vehicle.

Additional Material

While only a few embodiments of the present invention have been shownand described, it will be obvious to those skilled in the art that manychanges and modifications may be made thereunto without departing fromthe spirit and scope of the present invention as described in thefollowing claims. All patent applications and patents, both foreign anddomestic, and all other publications referenced herein are incorporatedherein in their entireties to the full extent permitted by law.

While the invention has been described in connection with certainpreferred embodiments, other embodiments would be understood by one ofordinary skill in the art and are encompassed herein.

The methods and systems described herein may be deployed in part or inwhole through a machine that executes computer software, program codes,and/or instructions on a processor. The present invention may beimplemented as a method on the machine, as a system or apparatus as partof or in relation to the machine, or as a computer program productembodied in a computer readable medium executing on one or more of themachines. The processor may be part of a server, client, networkinfrastructure, mobile computing platform, stationary computingplatform, or other computing platform. A processor may be any kind ofcomputational or processing device capable of executing programinstructions, codes, binary instructions and the like. The processor maybe or include a signal processor, digital processor, embedded processor,microprocessor or any variant such as a co-processor (math co-processor,graphic co-processor, communication co-processor and the like) and thelike that may directly or indirectly facilitate execution of programcode or program instructions stored thereon. In addition, the processormay enable execution of multiple programs, threads, and codes. Thethreads may be executed simultaneously to enhance the performance of theprocessor and to facilitate simultaneous operations of the application.By way of implementation, methods, program codes, program instructionsand the like described herein may be implemented in one or more thread.The thread may spawn other threads that may have assigned prioritiesassociated with them; the processor may execute these threads based onpriority or any other order based on instructions provided in theprogram code. The processor may include memory that stores methods,codes, instructions and programs as described herein and elsewhere. Theprocessor may access a storage medium through an interface that maystore methods, codes, and instructions as described herein andelsewhere. The storage medium associated with the processor for storingmethods, programs, codes, program instructions or other type ofinstructions capable of being executed by the computing or processingdevice may include but may not be limited to one or more of a CD-ROM,DVD, memory, hard disk, flash drive, RAM, ROM, cache and the like.

A processor may include one or more cores that may enhance speed andperformance of a multiprocessor. In embodiments, the process may be adual core processor, quad core processors, other chip-levelmultiprocessor and the like that combine two or more independent cores(called a die).

The methods and systems described herein may be deployed in part or inwhole through a machine that executes computer software on a server,client, firewall, gateway, hub, router, or other such computer and/ornetworking hardware. The software program may be associated with aserver that may include a file server, print server, domain server,internet server, intranet server and other variants such as secondaryserver, host server, distributed server and the like. The server mayinclude one or more of memories, processors, computer readable media,storage media, ports (physical and virtual), communication devices, andinterfaces capable of accessing other servers, clients, machines, anddevices through a wired or a wireless medium, and the like. The methods,programs or codes as described herein and elsewhere may be executed bythe server. In addition, other devices required for execution of methodsas described in this application may be considered as a part of theinfrastructure associated with the server.

The server may provide an interface to other devices including, withoutlimitation, clients, other servers, printers, database servers, printservers, file servers, communication servers, distributed servers andthe like. Additionally, this coupling and/or connection may facilitateremote execution of program across the network. The networking of someor all of these devices may facilitate parallel processing of a programor method at one or more location without deviating from the scope ofthe invention. In addition, any of the devices attached to the serverthrough an interface may include at least one storage medium capable ofstoring methods, programs, code and/or instructions. A centralrepository may provide program instructions to be executed on differentdevices. In this implementation, the remote repository may act as astorage medium for program code, instructions, and programs.

The software program may be associated with a client that may include afile client, print client, domain client, internet client, intranetclient and other variants such as secondary client, host client,distributed client and the like. The client may include one or more ofmemories, processors, computer readable media, storage media, ports(physical and virtual), communication devices, and interfaces capable ofaccessing other clients, servers, machines, and devices through a wiredor a wireless medium, and the like. The methods, programs or codes asdescribed herein and elsewhere may be executed by the client. Inaddition, other devices required for execution of methods as describedin this application may be considered as a part of the infrastructureassociated with the client.

The client may provide an interface to other devices including, withoutlimitation, servers, other clients, printers, database servers, printservers, file servers, communication servers, distributed servers andthe like. Additionally, this coupling and/or connection may facilitateremote execution of program across the network. The networking of someor all of these devices may facilitate parallel processing of a programor method at one or more location without deviating from the scope ofthe invention. In addition, any of the devices attached to the clientthrough an interface may include at least one storage medium capable ofstoring methods, programs, applications, code and/or instructions. Acentral repository may provide program instructions to be executed ondifferent devices. In this implementation, the remote repository may actas a storage medium for program code, instructions, and programs.

The methods and systems described herein may be deployed in part or inwhole through network infrastructures. The network infrastructure mayinclude elements such as computing devices, servers, routers, hubs,firewalls, clients, personal computers, communication devices, routingdevices and other active and passive devices, modules and/or componentsas known in the art. The computing and/or non-computing device(s)associated with the network infrastructure may include, apart from othercomponents, a storage medium such as flash memory, buffer, stack, RAM,ROM and the like. The processes, methods, program codes, instructionsdescribed herein and elsewhere may be executed by one or more of thenetwork infrastructural elements.

The methods, program codes, and instructions described herein andelsewhere may be implemented on a cellular network having multiplecells. The cellular network may either be frequency division multipleaccess (FDMA) networks or code division multiple access (CDMA) network.The cellular network may include mobile devices, cell sites, basestations, repeaters, antennas, towers, and the like. The cell networkmay be a GSM, GPRS, 3G, EVDO, mesh, or other networks types.

The methods, programs codes, and instructions described herein andelsewhere may be implemented on or through mobile devices. The mobiledevices may include navigation devices, cell phones, mobile phones,mobile personal digital assistants, laptops, palmtops, netbooks, pagers,electronic books readers, music players and the like. These devices mayinclude, apart from other components, a storage medium such as a flashmemory, buffer, RAM, ROM and one or more computing devices. Thecomputing devices associated with mobile devices may be enabled toexecute program codes, methods, and instructions stored thereon.Alternatively, the mobile devices may be configured to executeinstructions in collaboration with other devices. The mobile devices maycommunicate with base stations interfaced with servers and configured toexecute program codes. The mobile devices may communicate on apeer-to-peer network, mesh network, or other communications network. Theprogram code may be stored on the storage medium associated with theserver and executed by a computing device embedded within the server.The base station may include a computing device and a storage medium.The storage device may store program codes and instructions executed bythe computing devices associated with the base station.

The computer software, program codes, and/or instructions may be storedand/or accessed on machine readable media that may include: computercomponents, devices, and recording media that retain digital data usedfor computing for some interval of time; semiconductor storage known asrandom access memory (RAM); mass storage typically for more permanentstorage, such as optical discs, forms of magnetic storage like harddisks, tapes, drums, cards and other types; processor registers, cachememory, volatile memory, non-volatile memory; optical storage such asCD, DVD; removable media such as flash memory (e.g. USB sticks or keys),floppy disks, magnetic tape, paper tape, punch cards, standalone RAMdisks, Zip drives, removable mass storage, off-line, and the like; othercomputer memory such as dynamic memory, static memory, read/writestorage, mutable storage, read only, random access, sequential access,location addressable, file addressable, content addressable, networkattached storage, storage area network, bar codes, magnetic ink, and thelike.

The methods and systems described herein may transform physical and/oror intangible items from one state to another. The methods and systemsdescribed herein may also transform data representing physical and/orintangible items from one state to another.

The elements described and depicted herein, including in flow charts andblock diagrams throughout the figures, imply logical boundaries betweenthe elements. However, according to software or hardware engineeringpractices, the depicted elements and the functions thereof may beimplemented on machines through computer executable media having aprocessor capable of executing program instructions stored thereon as amonolithic software structure, as standalone software modules, or asmodules that employ external routines, code, services, and so forth, orany combination of these, and all such implementations may be within thescope of the present disclosure. Examples of such machines may include,but may not be limited to, personal digital assistants, laptops,personal computers, mobile phones, other handheld computing devices,medical equipment, wired or wireless communication devices, transducers,chips, calculators, satellites, tablet PCs, electronic books, gadgets,electronic devices, devices having artificial intelligence, computingdevices, networking equipment, servers, routers and the like.Furthermore, the elements depicted in the flow chart and block diagramsor any other logical component may be implemented on a machine capableof executing program instructions. Thus, while the foregoing drawingsand descriptions set forth functional aspects of the disclosed systems,no particular arrangement of software for implementing these functionalaspects should be inferred from these descriptions unless explicitlystated or otherwise clear from the context. Similarly, it will beappreciated that the various steps identified and described above may bevaried, and that the order of steps may be adapted to particularapplications of the techniques disclosed herein. All such variations andmodifications are intended to fall within the scope of this disclosure.As such, the depiction and/or description of an order for various stepsshould not be understood to require a particular order of execution forthose steps, unless required by a particular application, or explicitlystated or otherwise clear from the context.

The methods and/or processes described above, and steps thereof, may berealized in hardware, software or any combination of hardware andsoftware suitable for a particular application. The hardware may includea general-purpose computer and/or dedicated computing device or specificcomputing device or particular aspect or component of a specificcomputing device. The processes may be realized in one or moremicroprocessors, microcontrollers, embedded microcontrollers,programmable digital signal processors or other programmable device,along with internal and/or external memory. The processes may also, orinstead, be embodied in an application specific integrated circuit, aprogrammable gate array, programmable array logic, or any other deviceor combination of devices that may be configured to process electronicsignals. It will further be appreciated that one or more of theprocesses may be realized as a computer executable code capable of beingexecuted on a machine-readable medium.

The computer executable code may be created using a structuredprogramming language such as C, C#, an object oriented programminglanguage such as C++, or any other high-level or low-level programminglanguage (including assembly languages, hardware description languages,and database programming languages and technologies) that may be stored,compiled or interpreted to run on one of the above devices, as well asheterogeneous combinations of processors, processor architectures, orcombinations of different hardware and software, or any other machinecapable of executing program instructions.

Thus, in one aspect, each method described above and combinationsthereof may be embodied in computer executable code that, when executingon one or more computing devices, performs the steps thereof. In anotheraspect, the methods may be embodied in systems that perform the stepsthereof, and may be distributed across devices in a number of ways, orall of the functionality may be integrated into a dedicated, standalonedevice or other hardware. In another aspect, the means for performingthe steps associated with the processes described above may include anyof the hardware and/or software described above. All such permutationsand combinations are intended to fall within the scope of the presentdisclosure.

While the invention has been disclosed in connection with the preferredembodiments shown and described in detail, various modifications andimprovements thereon will become readily apparent to those skilled inthe art. Accordingly, the spirit and scope of the present invention isnot to be limited by the foregoing examples, but is to be understood inthe broadest sense allowable by law.

All documents referenced herein are hereby incorporated by reference.

The invention claimed is:
 1. A system for towing in tandem at least onetarget object located within a body of water, the system comprising: aplurality of autonomous marine platforms, wherein at least one of theautonomous marine platforms is an unmanned autonomous marine platform,each autonomous marine platform comprising: a propulsion and steeragesystem adapted to provide a propulsion speed and a direction of travelto the corresponding autonomous marine platform; a control systemstructured and arranged to provide signals to the propulsion andsteerage system; a mechanical connection between the correspondingautonomous marine platform and the target object; and at least onesensing device operatively coupled to the mechanical connection andstructured and arranged to sense at least one property of the mechanicalconnection and to communicate that sensed data; and an integratedcontrol system structured and arranged to control the propulsion speedand direction of travel off each autonomous marine platform and adaptedto: receive the sensed data from each sensing device; calculate, basedon the sensed data and at least one desired property of the mechanicalconnection of at least one autonomous marine platform, at least oneadjustment to be made to the corresponding autonomous marine platform;and transmit signals to the control system of at least one of theautonomous marine platforms to control at least one property of themechanical connection based on such calculation, so as to controlposition and orientation of the target object on the body of water. 2.The system of claim 1, wherein each of the autonomous marine platformsis unmanned.
 3. The system of claim 1, wherein the sensing devicecomprises at least one of a strain gauge sensor, a local measurementsystem, and a tension measurement system.
 4. The system of claim 3,wherein at least one of the strain gauge sensor, the local measurementsystem, and the tension measurement system is at least one of embeddedin and attached to the mechanical connection.
 5. The system of claim 3,wherein at least one of the strain gauge sensor, the local measurementsystem, and the tension measurement system monitors tension in themechanical connection continuously.
 6. The system of claim 3, wherein atleast one of the strain gauge sensor, the local measurement system, andthe tension measurement system monitors tension in the mechanicalconnection periodically.
 7. The system of claim 1, wherein the propertyof the mechanical connection comprises tension, and the integratedcontrol system controls tension in the mechanical connection byadjusting at least one of a heading, a propulsion thrust level, and adirection of propulsion of the corresponding marine platform.
 8. Thesystem of claim 1, wherein the property of the mechanical connectioncomprises length, and the integrated control system controls the lengthby adjusting a winch to at least one of lengthen and shorten the lengthof the mechanical connection.
 9. A method for towing in tandem at leastone target object located within a body of water using a plurality ofautonomous marine platforms, at least one of which is unmanned, eachautonomous marine platform comprising a propulsion and steerage systemadapted to provide a propulsion speed and a direction of travel to thecorresponding autonomous marine platform, a control system structuredand arranged to provide signals to the propulsion and steerage system, amechanical connection between the corresponding autonomous marineplatform and the target object, the method comprising: providing amechanical connection between each autonomous marine platform and thetarget object; operatively coupling at least one sensing device to themechanical connection; measuring a property of each mechanicalconnection; calculating, based on the measured property and at least onedesired property of the mechanical connection, at least one adjustmentto be made to the corresponding autonomous marine platform; andcontrolling, using an integrated control system and the calculatedadjustment, the corresponding autonomous marine platform and a positionand orientation of the target object on the body of water.
 10. Themethod of claim 9, wherein the sensing device comprises at least one ofa strain gauge sensor, a local measurement system, and a tensionmeasurement system and measuring a property of each mechanical propertycomprises measuring tension in the mechanical connection.
 11. The methodof claim 10, wherein at least one of the strain gauge sensor, the localmeasurement system, and the tension measurement system is at least oneof embedded in and attached to the mechanical connection.
 12. The methodclaim 10, wherein at least one of the strain gauge sensor, the localmeasurement system, and the tension measurement system measures tensionin the mechanical connection continuously.
 13. The method claim 10,wherein at least one of the strain gauge sensor, the local measurementsystem, and the tension measurement system measures tension in themechanical connection periodically.
 14. The method of claim 9, whereinthe property of the mechanical connection measured comprises tension,and the integrated control system controls tension in the mechanicalconnection by adjusting at least one of a heading, a propulsion thrustlevel, and a direction of propulsion of at least one of the marineplatforms.
 15. The method of claim 9, wherein the property of themechanical connection measured comprises length, and the integratedcontrol system controls the length by adjusting a winch to at least oneof lengthen and shorten the length of the mechanical connection of atleast one of the marine platforms.
 16. An integrated control system forcontrolling a plurality of autonomous marine platforms towing in tandemat least one target object located within a body of water, wherein atleast one of the autonomous marine platforms is an unmanned autonomousmarine platform and each autonomous marine platform comprising apropulsion and steerage system adapted to provide a propulsion speed anda direction of travel to the corresponding autonomous marine platform, acontrol system structured and arranged to provide signals to thepropulsion and steerage system, a mechanical connection between thecorresponding autonomous marine platform and the target object, and atleast one sensing device operatively coupled to the mechanicalconnection and structured and arranged to sense at least one property ofthe mechanical connections and to communicating that sensed data, theintegrated control system comprising: a non-volatile memory for storingcomputer-executable instructions for controlling the marine platformsand the target object; and a processing device configured to executesome portion of the instructions stored in the non-volatile memory, theexecuted instructions adapted to cause the processing device to: receivesensed data from each sensing device on each corresponding marineplatform; calculate, based on the sensed data and at least one desiredproperty of the mechanical connection of at least one autonomous marineplatform, at least one adjustment to be made to the correspondingautonomous marine platform and generate and transmit, based on suchcalculation, adjustment signals to the control system of at least one ofthe autonomous marine platforms to control at least one property of themechanical connection, so as to control a position and orientation ofthe target object on the body of water.
 17. The integrated controlsystem of claim 16, wherein the property of the mechanical connectioncomprises tension, and the integrated control system controls tension inthe mechanical connection by adjusting at least one of a heading, apropulsion thrust level, and a direction of propulsion of thecorresponding marine platform.
 18. The integrated control system ofclaim 16, wherein the property of the mechanical connection compriseslength, and the integrated control system controls the length byadjusting a winch to at least one of lengthen and shorten the length ofthe mechanical connection.